Subject to the provisions of this article and of articles 6 and 7 of this Order, the amount of the levy payable under an assessment notice served by the Board shall be due and payable to the Board one month after the date of the assessment notice.

The amount of an assessment shall not be recoverable by the Board until there has expired the time allowed for appealing against the assessment by article 7(1) of this Order and any further period or periods of time that the Board or an industrial tribunal may have allowed for appealing under paragraph (2) or (3) of that article or, where an appeal is brought, until the appeal is decided or withdrawn.